Large
numbers of middle-aged women worldwide could reduce their risk of
developing cardiovascular disease (stroke, heart attack and heart
failure) and its complications by lowering their blood pressure,
researchers report in Hypertension: Journal of the American Heart
Association.

Researchers
found that high systolic blood pressure (the pressure when the heart
contracts) is a powerful risk factor for cardiovascular complications
in middle-aged and older women all over the world.

The
proportion of potentially preventable and reversible heart disease is
almost 36 percent in women compared to 24 percent in men, as measured
by 24-hour systolic blood pressure monitoring, researchers said.

Investigators
in 11 countries, working on behalf of the International Database on
Ambulatory blood pressure in relation to Cardiovascular Outcomes
(IDACO), followed 9,357 adults (average age 53; 47 percent women)
throughout Europe, Asia and South America for more than 11 years. They
analyzed participants for absolute and relative risks of cardiovascular
disease associated with systolic blood pressure.

Three
major risk factors account for 85 percent of the modifiable
(reversible) risk for heart disease in women and men: high systolic
blood pressure, high cholesterol and smoking. High systolic pressure is
the most important risk factor.

"I
was surprised by the study findings that highlight the missed
opportunities for prevention of heart disease in older women," said Jan
A. Staessen, M.D., Ph.D., director of the StudiesCoordinating Center in
the Division of Cardiovascular Rehabilitation at the University of
Leuven in Belgium. "We found that a 15 mm Hg increase in systolic blood
pressure increased the risk of cardiovascular disease by 56 percent in
women compared to 32 percent in men."

Researchers
estimated the occurrences of cardiovascular disease in women and men
that are potentially preventable by lowering blood pressure. The
absolute and relative risks associated with high blood pressure were
assessed using both ambulatory 24-hour blood pressure monitoring and
conventional blood pressure measurements in the doctor's office.

Ambulatory
blood pressure monitoring involves measuring blood pressure for 24
hours during participants' daily routine and when asleep. The monitor
is a small, portable device programmed to record blood pressures at
specific intervals. Ambulatory blood pressure readings have less
potential for error and better reproducibility, and provide more
accurate estimates of usual blood pressure and prognosis for
cardiovascular disease than conventional blood pressure readings.

Ambulatory
blood pressure also provides information about blood pressure during
nighttime sleep and blood pressure variability. Ambulatory daytime
readings are recorded at intervals of about 15 to 30 minutes, while
nighttime readings are recorded at intervals of about 30 to 45 minutes.
Researchers said that nighttime blood pressure readings are a better
predictor of heart disease than daytime readings because readings are
more standardized at night than in the daytime. At night, blood
pressure is less likely to be influenced by physical activity.

"It
is recognized that women live longer than men, but that older women
usually report lower quality of life than men. By lowering systolic
pressure by 15 mm Hg in hypertensive women, there would be an increased
benefit in quality of life by the prevention of cardiovascular disease
in about 40 percent in women compared to 20 percent in men," Staessen
said.

He recommends that women and physicians become more aggressive in diagnosing and treating high systolic blood pressure.

Researchers
are enlarging the database to include other countries and ethnicities.
They are developing risk charts based on ambulatory blood pressure
recordings to be used by physicians in day-to-day clinical practice.